Bumper type auto jack



April 18, 1939- w. c. TYLER 2,155,157

BUMPER TYPE AUTO JACK Filed Feb. 5, 1936 2 Sheets-Sheet l 51 .90 I I11 II J25 y 25 I I I I I I I I I I II I I II I II II IIJII I I IIIIII I[7Z?/e7Z771' III IIIIIIIIIIII I '%;If e

April 18, 1939. w. c. TYLER BUMPER TYPE AUTO JACK 2 SheetS -Sheet 2 IFiled Feb. '5, 1936 Patented Apr. 18, 1939 UNITED STATES.

BUMPER TYPE AUTO JACK William 0. Tyler, Joliet, 1 11., assig-nor toWilliam E. Pratt Mfg. 60., Joliet, 111., a corporation of IllinoisApplication February 3, 1986, Serial No. 62,196

5 Claims.

This invention relates to screw jacks. The particular embodiment shownis of a type well adapted to lifting an automobile at a bumper, but theinvention may be adapted to other types and different uses.

An object of the invention is to provide a jack which is simple andconvenient, and which requires only a minimum amount of time and effortto operate. Another object is to provide a screw jack in which most ofthe working parts are enclosed in such a manner as to exclude dirt,grit, etc. A further object is to provide a new jack construction whichis adjustable to particular :needs and which is adapted to securely holdthe object to be raised. Other objects and advantages will appear as thespecification proceeds.

The invention is illustrated in a preferred embodiment in theaccompanying drawings in which- Figure 1 is a front View in elevation;Figure 2, aztop plan view'of the upper portion; Figure 3, a verticalsectional view taken at line 3 of Figure 2; and Figure 4, a top viewsimilar to Figure 2, but with the head and bearing removed.

.In the illustration given, A designates a jack casing which is providedwith a base A and a bore A B designates the screw means, C designatesthe driving mechanism, and D designates the 'head.

The jack casing A may be of any well known construction and material.The height of the casing and the size of the base A arefactors which maybe varied according to the particular conditions under which the jack isto be operated. At .the top part of the casing are internal threads Iadapted to receive screw means B.

In the illustration given, the screw means B is shown as of thedouble-lift type and comprises an inner screw I5 and outer screw l l.The outer screw II is hollow and sleeve-like in character. Its externalsurface has threads !2 throughout its length except for a shortunthreaded portion I 3 at its lower end. Its internal surface iscylindrical in form with internal threads i l at its upper portion. Theinner screw is provided with external threads I6 which extend throughoutits length except for the extreme top portion and the short unthreadedportion IT at its lower end. External threads [2 on the outer screw areadapted to engage internal threads it of the casing, and externalthreads 16 of the inner screw are adapted to engage internal threads Mof the outer screw. The edges of the threaded portions of the screws areprovided with shoulders or stops to eliminate binding when the screw hasreached its limit. If desired, the extreme ends of the threads may beturned inward to form stops, inwhich construction the unthreadedportions maybe omitted.

The top portionrof screw I5 has an extension l8 which has flattenedsides. Above extension I8 is a cylindrical extension l9 which isprovided with a tapped screw hole 20 in the end.

The-drive mechanism C consists of a drive gear 2.1 rotatably iastenedinside a housing '22 in which housing is also a beveled gear member 23.A lower-cylindrical extension of drive gear 2| is arranged to fit downinto the bottom of housing 212 and be fastened there free to rotate bymeans of .a split ring :24 and aligned annular grooves 25.

.All .of mechanism C is adapted to be mounted on the top portion ofscrew 15. As shown in Fig-. ure 4, drive .gear2l has :a central openingallowingJitto be fitted down over the flattened extention t8 :of theinner screw. When mounted in this way, rotation of drive gear 211 willcause rotationiofscrew 1.5,, :but will not cause rotation of housing 22.

A beveled gear member 23 is rotatably secured in housing .22, :and isadapted to be actuated by a crank or shaft =.(-not shown), and to engagewith and cause rotation of drive gear 2|.

The head D has a countersunk central opening allowing .it to :fit downover the cylindrical extension 1.9 and a screw 26 with a washer 2! isemployed to prevent accidental detachment. Thecircular edge 'oihead D isprovided with teeth 28 which are arranged to fit down into correspondingdepressions 29 in the upper circular edge of housing 22. The top of headD is provided with a raised portion 30 which has ,a slot. or groove 3|.Groove 3| is intended to securely engage the bumper of an automobile orother object to be raised.

Adjustment of the angular position of the groove 3| is effected byraising the head sufliciently to disengage teeth 28 and rotating thehead to the desired position where teeth 28 may again engage depressionsin housing 22. An annular skirt 32 helps to guide this movement and toprevent dislocation of the head.

The weight of the object lifted and the weightof head D is supported onthe screw l5 preferably by means of a bearing 33 between drive gear 2|and head D. The bearing employed in the present illustration consists oftwo annular rings between which steel balls are allowed to roll inannular grooves. The under side of the head and the top of the drivegear 2! are fashioned to accommodate this bearing.

In the operation of the jack, the rotation of the beveled gear member 23causes rotation of drive gear 2| and screw I5. Rotation of screw I5 isaccompanied by elevation of this screw and also of the head D and drivemechanism C. Such operation may continue until the unthreaded portion l1impinges the shoulder of threads H, at which time screw II is caused torotate along with screw l5, and the elevation of the head and drivemechanism continues until the unthreaded portion I3 impinges theshoulder of threads ID.

The lowering of the jack may be effected by rotation of the crank orother actuating means in an opposite direction. After the load isremoved, the crank may be taken ofi and the jack easily reduced tocollapsed condition by simply setting the head and housing in rotation,the momentum of these parts helping the screw to rotate until the jackis collapsed.

' In operating this jack, the operator need not stoop all the while, foras the jack is operated the driving gears are raised, and the operatormay conveniently assume a slightly diiferent position. This feature isfound to make the jack less tiresome on the person who operates it.-

Another important operating feature is that after the base has been set,the angle at which the drive mechanism is operated may be changed tosuit the convenience of the operator, the position of the base remainingfixed. This feature is especially appreciated when the jack is operatedin close or awkward quarters.

Also the head may be adjusted so that it is in a position to hold firmlyto the bumper or other object to be lifted at any convenient angle ofthe drive mechanism. Such construction eliminates the common trouble ofhaving thehead slip and the load fall off while the jack is .inoperation; thus the jack is one highly desirable from the standpoint ofsafety.

The foregoing detailed description has been given for clearness ofunderstanding only and no unnecessary limitations should be understoodtherefrom, but the appended claims should be construed as broadly aspermissible in view of the prior art.

I claim:

1. A jack comprising a hollow casing, screw means engaging with theinterior of said casing, a housing, drive gears in said housing foractuating said screw means, said housing being mounted on one side ofsaid drive gears, and a head rotatably supported on said screw means,said head being in releasable engagement with said housing to preventrotation with respect thereto when a weight is supported on said head,said head and housing being inseparable vertically through operation oisaid screw means.

2. A jack comprising: a hollow casing; a hollow screw engaging theinterior of said casing; an inner screw engaging the interior of saidhollow screw; drive mechanism mounted on said inner screw, said drivemechanism including driving gears and a housing which is rotatablysupported by said inner screw and which is provided at its upper edgewith spaced notches; and a head rotatably supported by said inner screw,said head being provided at its edge with teeth adapted to engage thespaced notches in said housing.

3. A jack comprising a hollow casing having a base at the bottomthereof, said base being fixed with respect to said casing, a hollowscrew engaging the interior of said casing, an inner screw engaging theinterior of said hollow screw, a drive gear secured tosaid inner screw,means for actuating said drive gear, a housing enclosing said meansrotatably supported by said inner screw, and a head rotatably supportedon said drive gear, said head being provided with means for releasablyengaging said housing and preventing rotation with respect thereto.

4. A jack comprising: a hollow casing; a hollow screw engaging theinterior of said casing; an inner screw engaging the interior of saidhollow screw; drive gears carried by said inner screw, a housing membersupported by said inner screw and having upwardly extending edges, and ahead rotatably supported by said inner screw, the edges of said head andhousing being provided with interengaging teeth by which relativerotation of said head and housing is prevented while said head is underload, said head having a skirt portion engaging the interior of saidhousing adjacent said interengaging teeth.

5. A jack comprising: a hollow casing; screw means engaging the interiorof said casing, a housing rotatably mounted on said screw means, drivegears within said housing for rotating said screw means, a headrotatably supported on said screw means and having a central passagethere- I

